Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: If you bring together the entire world population and split the
people into groups of 365 people, 1% of the people can be placed into groups
composed of entirely unique birthdays.

Replies: 2   Last Post: Jan 26, 2013 3:44 PM

 Messages: [ Previous | Next ]
 Posts: 822 Registered: 9/1/10
Re: If you bring together the entire world population and split the
people into groups of 365 people, 1% of the people can be placed into groups
composed of entirely unique birthdays.

Posted: Jan 26, 2013 3:44 PM

On Jan 26, 8:07 am, karl <oud...@nononet.com> wrote:
> Am 26.01.2013 12:56, schrieb Musatov:> Bringing together any possible group of 366 people guarantees with
> > 100% certainty two people will share the same birthday.
>
>   wrong. You have, including the 29th February, 366 different dates for a birthday.

No, I just prove the existence of the false calculation of a
distributive cycle of an extra day and the entire existence of the 400
day Devonian period per research The fish of the Devonian Period
experienced rather short days. We know that the Devonian year had 400
days, making each day only 22 hours long.(72 kb) This just goes to
show that nothing is constant on Earth, not even the length of a day!
Just as continents move and change direction, the speed at which our
planet rotates also changes over time.

How is this possible? It is really the fault of the Moon, our
celestial companion. Since it formed 4.2 billion years ago (4.2 Ga),
the Moon has driven the tides on our planet. The Moon?s gravitational
pull attracts great masses of water toward it while in orbit around
us. As the Earth turns eastward, the tides move westward, and this
phenomenon imperceptibly slows the rotation of our planet by 0.0016
seconds per century!

Our planet was therefore turning faster in the past, such that each
year consisted of more, but shorter, days. Though the features of the
Earth may change, the laws of physics are constant. In a binary system
like the Earth and Moon, if one of the two companions loses momentum,
the other must gain momentum. Over time, as Earth?s rotation slows,
the orbital velocity of the Moon increases, forcing it to gradually
recede away from us. Using lasers, we have confirmed this movement and
found it to be 3.8 centimetres per year. This may seem too small to
make a real difference, but when added up over hundreds of millions of
years, we can calculate that the Moon is now twice as far from Earth
as it was during Devonian time. As a consequence, Devonian tides were
up to seven times larger than today?s tides.

These physics calculations have been verified by paleontological
discoveries. One line of evidence comes from corals. Corals, both
living and fossilized, are animals that live inside little cups of
calcium carbonate (calcite; CaCo3) that they themselves secrete. The
coral ?skeleton? grows because the animals deposit calcite every day
they are alive. The activity temporarily stops at night because the
animals live symbiotically with single-celled algae that need light to
function. The daily layers are visible under a microscope, making it
possible to count days, somewhat like counting tree rings to determine
the passage of years.

Species that live in temperate waters are subjected to seasonal
variations in temperature, so winter growth is slower and the marks
farther apart. Years are therefore easily distinguished among the
series of growth lines. A modern coral would show us years consisting
of 365 lines.

Coral fossils living 400 million years ago (400 Ma) in the Early
Devonian display years of 400 lines, and thus 400 days, proving that
the Earth did indeed turn faster at that time. For corals that lived
during the Upper Carboniferous (300 Ma), there are approximately 380
lines each year. The fossil record thus clearly demonstrates that
Earth?s rotation has gradually slowed over time, and that it is still
slowing down today.http://www.miguasha.ca/mig-en/a_devonian_day.php

On Sat, Jan 26, 2013 at 8:50 AM, Brian Gordon <briang@panix.com>
wrote:
In article <360bc663-7c17-4f13-9677-
>Bringing together any possible group of 366 people guarantees with
>100% certainty two people will share the same birthday.

Close, but no cigar. You forgot about February 29, so it takes 367
for certainty :-)

--
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++++++
| Brian Gordon -->briang@panix.com<-- brian dot gordon at cox
dot net |
+ brianggordon@hotmail.com Bass: Lexington "Main Street Harmonizers"
chorus +
-------------------------------------------------------------------------------

--
Martin Musatov

Tel: (818) 430-4586
E-mail: marty.musatov@gmail.com

Date Subject Author
1/26/13
1/26/13 karl
1/26/13